23. Bring your own coffee cupWe hear a lot about bringing our own water bottle, but the coffee cup is just as important. Avoid Styrofoam cups at work or catered meetings by bringing your own travel mug. Also, most gas stations and coffee shops will allow you to use your own cup and sometimes at a discounted price. If you are a daily coffee drinker like I am, by switching to your own reusable cup you'll avoid a lot of unnecessary trash.